On 2 May this year, I set off to walk from Liverpool to London, a journey of 340 miles that would take me a month. I was walking in the footsteps of the People’s March for Jobs, a column of 300-odd unemployed men and women who, on the same day in 1981, exactly 35 years previously, had set off from the steps of St George’s Hall to walk to Trafalgar Square.

In the two years after Margaret Thatcher had been elected, unemployment had gone from 1 to 3 million, as her policies laid waste to Britain’s manufacturing base. In 1981, we saw Rupert Murdoch buy the Times and Sunday Times. We witnessed inner-city riots, unprecedented in their scale and violence, in Liverpool and London. The formation of the SDP split the left. The Tories lost their first assault on the coal miners, capitulating over the closure of 23 pits.

My father, Pete Carter, was one of those who organised the original walk. My journey was an attempt to work out what had happened to Britain in the intervening years. What I saw and heard gave me an alarming sense of how the immense social changes wrought by Thatcherism are still having a profound effect on communities all over England. It also meant that when I awoke last Friday to the result of the EU referendum, I wasn’t remotely surprised.

Some of those charity shops had closed down. What does it say about a town when even the charity shops are struggling?

I left Liverpool the week of the Hillsborough inquest verdict, flowers and scarves still adorning lampposts. The inquest had finally vindicated the families of the 96 killed at the 1989 FA Cup semi-final, exposing the lies and cover-ups of the police, the media and the political class, who had spent over a quarter of a century traducing not only those fans, mostly working class, but also the city and its people. In fact, that demonising had found expression in 1981, too, when Geoffrey Howe suggested to Thatcher privately that, after the Toxteth riots, Liverpool should be subject to a “managed decline”.

I walked through Widnes and Warrington, past huge out-of-town shopping centres and through the wastelands of industrial decay. In Salford, down streets where all the pubs were boarded up and local shops, if you could find them, had brick walls for windows and prison-like metal doors, I found an Airbnb. My host was selling her terraced house. I sat in her living room as the estate agent brought around potential buyers. They were all buy-to-let investors from the south of England, building property portfolios in the poverty, as if this was one giant fire sale.

‘In Salford, down streets where all the pubs were boarded up and local shops, if you could find one, had brick walls for windows and prison-like metal doors, I found an AirBnB.’ Photograph: Don McPhee for the Guardian

On I walked. Through Stockport, Macclesfield, Congleton. The flag of St George flew, from flagpoles, from guttering. Leave posters were everywhere. I didn’t see a single one for remain.

Just before Stoke-on-Trent, I passed the immense workings of the Chatterley Whitfield Colliery, closed down in the 1970s. The mine, one of Europe’s largest, had become a heritage centre and museum. In 1993 even that had shut.

In Hanley, I started asking people what they thought about the referendum and if they wouldn’t mind telling me how they’d be voting. There was little reticence. “Out,” they would say. “No question.”

“Why?” I’d ask.

“Immigration,” would come the response. “We want our country back.”

The Potteries museum opened in 1981, the year of the People’s March. There I read about Stoke’s industrial heritage, the ceramics, the coal mines, the steel industry, employing tens of thousands of people. All gone now.

Stafford, Cannock, Wolverhampton. Different towns, same message: “There’s no decent work”; “the politicians don’t care about us”; “we’ve been forgotten”; “betrayed”; “there’s too many immigrants, and we can’t compete with the wages they’ll work for”. Nobody used the word humiliation, but that’s the sense I got.

In Wolverhampton, the Express and Star newspaper was reporting on the fury from Wolves fans at the football club’s new shirt sponsor. It was to be the Money Shop, a payday lender. In Walsall, where I went to college, I walked around a town centre unrecognisable from 30 years earlier. Everywhere there were betting shops, dozens of them, and right next door to every betting shop was a pawnbroker or payday lender. It was a ghoulish form of mutualism, or symbiosis, the “natural” market at its most efficient.

And there was another thing I noticed about all of these towns: the ubiquity of mobility scooters, and not all of them being driven by the elderly. Was this a manifestation of the established links between poverty and ill health?

I walked on. Birmingham glittered, a skyline of cranes and high streets of fashionable shops, a confidence, a bounce. But out of the city centre the familiar motifs returned: boarded up pubs and shuttered shops, leave posters in windows, and a proliferation of hand car washes. It began to make sense why these have blossomed in modern Britain: why invest in expensive automated machinery when labour can be sourced so cheaply.

Nuneaton, the home town of George Eliot and Ken Loach, had more charity shops in its high street than anywhere I’ve ever seen. And some of those charity shops had closed down. What does it say about a town when even the charity shops are struggling?

‘I started asking people if they wouldn’t mind telling me how they’d be voting. There was little reticence. “Out,” they would say. “Why?” I’d ask. “Immigration,” would come the response.’ Photograph: Matt Cardy/Getty Images

In Coventry, whose car industry is now mostly gone, there seemed to be a construction frenzy. These were mostly new buildings for the colleges and universities, competing not only for a bigger share of domestic students but also for the lucrative foreign student market. A friend doing an MA in the city told me that 90% of the students on his course were from overseas, and the majority of them Chinese.

As I moved south, I thought that the economic picture might change, but in Rugby, Bedford, Luton the high streets all had the by now familiar composition: betting shops, fast-food outlets, tattoo parlours. And the answer to the question “in” or “out” never changed either. “We’ve been left behind,” a white, middle-aged man told me at a bus stop as I rested in Hemel Hempstead. “Those politicians don’t care about us. Immigration has ruined this country.”

I walked into central London, through Chiswick, past people sitting at pavement cafes, shops selling expensive furniture, estate agents offering two-bedroom flats for a million pounds. Through Hyde Park and on to Wellington Arch, with all the pomp and puffery of empire, and then Buckingham Palace, as tourists lapped up the pageantry. I was in, literally and spiritually, another country.

In 1935, a young Laurie Lee set off to walk across Spain, from north to south. In the book the adventure would eventually lead to, As I Walked Out One Midsummer Morning, Lee describes a country riven by inequality, of communities in grinding poverty, and an out-of-touch ruling elite. The fascists and the communists both laid claim to the discontents, the rhetoric becoming increasingly polarised. The narrative resonated across the European continent. By the time Lee got to Malaga, in the summer of 1936, the Spanish civil war had begun.

A student by the gates of Downing Street approached Mike Carter and asked him if he could tell her who was pictured on her worksheet. It was Margaret Thatcher. Photograph: Mike Carter

I thought about Lee’s journey, about Europe in the 1930s and 40s, and thanked God for the 70 years of peace we’d had since. I walked up Whitehall. On 30 May 1981, Thatcher had refused to meet the marchers to accept their 250,000-strong petition. On 30 May 2016, I paused at Downing Street, all high fences and machine guns now, and spoke to one of the armed officers. He told me about the attacks on police pensions, about the terrible morale these days in the force.

A girl came up, spoke in faltering English. She was on a school trip from Belgium. She had a project to complete, she said. Could I help her? She held up a piece of A4 paper. “Can you tell me who this is, please?” On it was a photograph of Margaret Thatcher.